#include<iostream>
#include<stack>
using namespace std;
int main()
{
    stack<int> is;
    for (int i = 0; i < 100; i++)
    {
        is.push(i);
    }
    cout<<"栈顶元素："<<is.top()<<endl;
    for (int i = 0; i < 20; i++)
    {
        is.pop();
    }
    cout<<"新的栈顶元素："<<is.top()<<endl;
    cout<<"尺寸："<<is.size()<<endl;
}

